Benedict’s test is based upon the participation of the aldehyde and ketone groups in a chemical reaction. In this
procedure, Benedict’s reagent, which contains a basic solution of cupric ions, is mixed with a sugar. The copper ions
will attract the electrons from the aldehyde or ketone group changing the charged copper ions to a neutral metal.
Copper ions are blue in color whereas copper metal is orange. Disaccharides will react with the Benedict’s reagent only
if it contains an exposed aldehyde or ketone group. This type of sugar is known as a reducing sugar.